Mathematics, computer science, computer graphics, pattern recognition and communication systems are topics I really like, as well as some creative work, mostly woodwork, sometimes raytracing.
Mathematica
Q&A for users of Wolfram Mathematica
Stack Overflow
Q&A for professional and enthusiast programmers
Super User
Q&A for computer enthusiasts and power users
Meta Stack Exchange
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Gardening & Landscaping
Q&A for gardeners and landscapers
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Mathematics
Q&A for people studying math at any level and professionals in related fields
Database Administrators
Q&A for database professionals who wish to improve their database skills and learn from others in the community
TeX - LaTeX
Q&A for users of TeX, LaTeX, ConTeXt, and related typesetting systems
Server Fault
Q&A for system and network administrators
SharePoint
Q&A for SharePoint enthusiasts
Physics
Q&A for active researchers, academics and students of physics
Unix & Linux
Q&A for users of Linux, FreeBSD and other Un*x-like operating systems
Internet of Things
Q&A for builders and users of networked sensors and control devices in the contexts of smart homes, industry automation, or environmental sensors
Android Enthusiasts
Q&A for enthusiasts and power users of the Android operating system
MathOverflow
Q&A for professional mathematicians
The Workplace
Q&A for members of the workforce navigating the professional setting
Aviation
Q&A for aircraft pilots, mechanics, and enthusiasts
Space Exploration
Q&A for spacecraft operators, scientists, engineers, and enthusiasts
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts